Photosensitizing Effect Research Articles

Treatment of caries affected dentin with different photosensitizers and its effect on adhesive bond integrity to resin composite.

The aim of the present study was to evaluate the effect of different photosensitizers activated by photodynamic therapy (PDT) on shear bond strength (SBS) of composite resin on caries affected dentin compared to conventional cavity disinfectants. Forty carious mandibular teeth were collected through non-traumatic extraction. All samples were embedded in polyvinyl cross-sections to the cemento-enamel junction. The preparation of caries-affected dentin was performed by grinding the specimens using silicon carbide discs. All specimens were arbitrarily allocated in to four groups (n = 10). Group 1, affected dentin disinfected with methylene blue (MB) [100 mg/L]; Group 2, caries affected dentin disinfected using curcumin photosensitizer (CP) [500 mg/L]; Group 3, affected dentin disinfected with indocyanin green photosensitizer (ICGP) [0.5 mL] Group 4, affected dentin treated with 3 % H2O2. Two-step self-etch adhesives was smeared on all specimens for 15 s and photopolymerized for 10 s. All specimens were placed in an incubator with humid environment for 24 h at 37 °C followed by positioning in universal testing machine for SBS testing. Failure mode examination of debonded samples was performed by a stereomicroscope. Analysis of variance (ANOVA) was used for inter group comparison through mean and standard deviation of each group. For multiple group comparison Tukey HSD was employed. Level of significance was established at p < 0.05. In group 2 dentin disinfection using CP, displayed the highest SBS value (18.21 ± 1.39 MPa). Whereas, group 4 (3% H2O2 as cavity disinfectant) presented the lowest SBS values (13.39 ± 1.26 MPa). SBS in Group 3 (ICGP) (17.42 ± 0.55 MPa) specimens was comparable to group 2 (p > 0.05) samples. In group 1, samples disinfected with MB (15.18 ± 0.39 MPa) was found to be significantly lower compared to group 2 and group 3 (p < 0.05) respectively. Curcumin and Indocyanin green (ICGP) PS have the potential to be used as cavity disinfectant as it improves SBS of caries affected dentin to resin composite. Photodynamic therapy for disinfection of caries affected dentin will augment its bond strength, however its long-term effect on bond integrity still needs to be investigated.

Nanoceria-curcumin conjugate: Synthesis and selective cytotoxicity against cancer cells under oxidative stress conditions

A water- and alcohol-soluble cerium oxide-curcumin conjugate was obtained by co-evaporation with poly(N-vinylpyrrolidone) (PVP). A nanocomposite consisting of hybrid organic-inorganic particles was stable in a wide range of pH values. Its properties were evaluated using nine cell lines: normal (MDBK, ST, Vero) and malignant (L929, T98G, HEp-2, A549, RIN-m5F, Hep G2). PVP-stabilised nanoceria was shown to inhibit autoxidation of curcumin, to enhance curcumin photostability, to promote bioaccumulation and to affect curcumin cytotoxicity and photocytotoxicity, depending on cell type, being more toxic to cancer cells in a selective manner. Under the conditions of UVA/UVC or H2O2-induced oxidative stress, the nanoceria-PVP-curcumin (NPC) conjugate was found to possess a selective cytotoxicity: it caused drastic inhibition of metabolic activity or a decrease in the total number of tumour cells, while in non-transformed cultures under the same conditions, the nanoceria-PVP-curcumin conjugate protected cells from these damaging factors. The NPC-conjugate, unlike curcumin itself, demonstrated a photosensitising effect in tumour cell cultures, while protecting non-transformed cultures from the damaging effects of UV radiation or oxidative stress. Based on the results obtained, we strongly believe that this novel hybrid material has enhanced characteristics compared to other curcumin formulations, and can be considered as a potent drug for biomedical applications, including cancer therapy.

Engineered algae: A novel oxygen-generating system for effective treatment of hypoxic cancer.

Microalgae, a naturally present unicellular microorganism, can undergo light photosynthesis and have been used in biofuels, nutrition, etc. Here, we report that engineered live microalgae can be delivered to hypoxic tumor regions to increase local oxygen levels and resensitize resistant cancer cells to both radio- and phototherapies. We demonstrate that the hypoxic environment in tumors is markedly improved by in situ-generated oxygen through microalgae-mediated photosynthesis, resulting in notably radiotherapeutic efficacy. Furthermore, the chlorophyll from microalgae produces reactive oxygen species during laser irradiation, further augmenting the photosensitizing effect and enhancing tumor cell apoptosis. Thus, the sequential combination of oxygen-generating algae system with radio- and phototherapies has the potential to create an innovative treatment strategy to improve the outcome of cancer management. Together, our findings demonstrate a novel approach that leverages the products of photosynthesis for treatment of tumors and provide proof-of-concept evidence for future development of algae-enhanced radio- and photodynamic therapy.

Wavelength-sensitive photocatalytic H2 evolution from H2S splitting over g-C3N4 with S,N-codoped carbon dots as the photosensitizer

Activity enhancement of S,N codoped carbon dots (S,N-CDs) on g-C 3 N 4 for photocatalytic H 2 evolution from H 2 S splitting is heavily dependent on the wavelength of the incident light due to their dominant photosensitization effect. • S,N-CDs improve the photocatalytic activity of g-C 3 N 4 for H 2 S splitting by 38 times. • S,N-CDs selectively improve the activity of g-C 3 N 4 and do best at 460 nm. • Photosensitization plays the dominant role for activity enhancement. • Energy level match of S,N-CDs and g-C 3 N 4 is vital for effective H 2 evolution. Photocatalytic splitting of hydrogen sulfide (H 2 S) for hydrogen evolution is a promising method to solve the energy and environmental issues. In this work, S,N-codoped carbon dots (S,N-CDs)/graphitic carbon nitride (g-C 3 N 4 ) nanosheet is synthesized by hydrothermal method as an efficient photocatalyst for the decomposition of H 2 S. In addition to the characterization of the morphology and structure, chemical state, optical and electrochemical performances of S,N-CDs/g-C 3 N 4 , hydrogen evolution tests show that the activity of g-C 3 N 4 is improved by introducing S,N-CDs, and the enhancement depends strongly on the wavelength of incident light. The photocatalytic hydrogen production rate of S,N-CDs/g-C 3 N 4 composite reaches 832 μmol g −1 h −1 , which is 38 times to that of g-C 3 N 4 under irradiation at 460 nm. Density functional theory calculations and electron paramagnetic resonance as well as photoluminescence technologies have altogether authenticated that the unique wavelength-dependent photosensitization of S,N-CDs on g-C 3 N 4 ; meanwhile, a good match between the energy level of S,N-CDs and g-C 3 N 4 is pivotal for the effective photocatalytic activity. Our work has unveiled the detailed mechanism of the photocatalytic activity enhancement in S,N-CDs/g-C 3 N 4 composite and showed its potential in photocatalytic splitting of H 2 S for hydrogen evolution.

Fabrication of CdS Nanorods on Si Pyramid Surface for Photosensitive Application.

It is the first time that cadmium sulfide (CdS) nanorods have been fabricated on silicon (Si) pyramid surface by the hydrothermal reaction method. In our work, the Si pyramid morphology is able to increase the adhesion between the CdS seed layer and Si wafer. Hence, it is critical for CdS nanorods to grow successfully. During the fabrication process, the glutathione is used as the complexing agent for the formation of the CdS nanorods. By continuously adjusting the experimental conditions, the thickness of the CdS seed layer, the concentration of the glutathione, and the temperature and time of the hydrothermal reaction, the optimal condition for CdS nanorods growth on Si pyramid surface is 80 nm seed layer, 0.2–0.3 mmol glutathione, 200 °C, and 1.5 h. The Cd and S elements have a ratio of 1:1.03 from the energy-dispersive spectroscopy test, which is in agreement with the stoichiometric composition of CdS. The CdS nanorods have a bandwidth of 2.22 eV through the optical absorption spectra. The photosensitivity response test results reveal these CdS nanorods on the Si pyramid structure have an obvious photosensitive effect. From the analysis, the CdS nanorods can grow on any morphological Si surface if the adhesion between the CdS seed layer and the Si surface is strong enough.

Influence of different photosensitizers on push-out bond strength of fiber post to radicular dentin

To evaluate the effect of different photosensitizer on extrusion bond strength of glass fiber post to radicular dentin. Forty maxillary and mandibular central incisors were disinfected and decoronated. Mechanical instrumentation of canal was performed using protaper NiTi. Shaping and cleaning of canal comprised of S1, S2, SX with finishing files F1 and F2, followed by continuous irrigation. Canals were dried and obturated with gutta percha. Peso reamers were used to prepare post space. Based on the photosensitizers (PS) used, the samples were divided into three groups (n = 10). Group 1: treated with methylene blue photosensitizer (MBP) at 50 mg/l, Group 2: Curcumin photosensitizer (CP) at 500 mg/l, Group 3: canal space was filled with Toluidine blue photosensitizer (TB) at 100 mg/l. All photosensitizers were activated using different lasers. The samples in group 4 (control) were irrigated using 5.25% sodium hypochlorite (NaOCl) + 17% ethylenediamine tetra acetic acid (EDTA). Posts were cemented and teeth were sectioned into coronal, middle and apical sections. All sections were placed in universal testing machine to evaluate extrusion bond strength in megapascal (MPa). Fracture pattern analysis of samples were seen under stereomicroscope at 50x magnification and categorized into adhesive, cohesive and admixed. Assessment of extrusion bond strength was performed by one-way analysis of variance (ANOVA) and Tukey multiple comparison test (p = 0.05). The highest bond strength was achieved in group 2, including samples treated with curcumin photosensitizer (CP) at all three root levels; cervical (9.01 ± 1.62 MPa), middle (7.95 ± 0.75 MPa) and apical (5.81 ± 0.15 MPa). Whereas, the lowest extrusion bond strength was observed in group 4 (canal irrigated with conventional 5.25% NaOCl +17% EDTA) at coronal (6.10 ± 1.77 MPa), middle (5.11 ± 0.75 MPa) and apical one-thirds (3.65 ± 0.14 MPa). Intra group comparison revealed decrease in extrusion bond strength from coronal to apical direction. Moreover, both group 2 and group 3 showed statistically significant difference to samples in control group and group 1. (p < 0.05). TB and CP at concentration of 100 mg/l and 500 mg/l has the potential to be used as an alternate to conventional cleaning regime. TB and CP at this concentration when activated with PDT is likely to improve extrusion bond values.

Photosensitive n-Type Doping Using Perovskite CsPbX3 Quantum Dots for Two-Dimensional MSe2 (M = Mo and W) Field-Effect Transistors.

Perovskite CsPbX3 (X = Br, Cl, and I) nanostructures have been intensively studied as they are luminescent, photovoltaic, and photosensitizing active materials. Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) with MX2 (M = Mo, W; X = S, Se, Te, etc.) structures have been used in flexible optoelectronic devices. In this study, perovskite green-light-emitting CsPbBr2I1 quantum dots (QDs) and blue-light-emitting CsPb(Cl/Br)3-QDs are utilized to enhance the photoresponsive characteristics of 2D MSe2 (M = Mo and W)-based field-effect transistors (FETs). From laser confocal microscopy photoluminescence (PL) experiments, PL quenching of the perovskite CsPb(Cl/Br)3-QDs and CsPbBr2I1-QDs is observed after hybridization with MoSe2 and WSe2 layers, respectively, which reflects the charge-transfer effect. According to the characteristics of the FETs based on the WSe2, MoSe2, WSe2/CsPbBr2I1-QDs hybrid, and MoSe2/CsPb(Cl/Br)3-QDs hybrid, the p-channel current (with hole mobility) is considerably decreased after the hybridization with the QDs. Notably, under incident light, the n-channel photocurrent and photoresponsivity of the FET are substantially increased, and the threshold voltage is negatively shifted owing to the hybridization with the perovskite QDs. The results show that the photosensitive n-type doping effect on the 2D MoSe2 and WSe2 nanosystems originates from the photogating effect by the trap states after the hybridization with various perovskite CsPbX3-QDs.

Multipath energy transfer and NIR luminescent properties of dual-lanthanide complexes

Near infrared (NIR)-emitting lanthanide ions, especially Sm3+, Nd3+, Yb3+, and Er3+, show special advantages in non-damage and deep-reaching biological imaging and telecommunication field. But most lanthanide ions have low luminescent efficiency in the NIR region, as a result of insufficient protection of the metal centers against non-radiative deactivation processes and/or inefficient inter- or intramolecular energy transfer. In recent years, organic ligands have been used as antennas to sensitize lanthanide ions to improve their luminescent efficiency. Because the chemical properties of lanthanide ions are very similar, mixed lanthanide complexes can be formed. At the same time, lanthanide ions have many energy levels, the energy transfer is easy to occur between different lanthanide ions. Thus, we can make use of these multi-path energy transfers to obtain efficient dual/multi-lanthanide multi-component NIR luminescent materials, which can be used for the ideal multi-channel near-infrared luminescence anti-counterfeiting bar code application. Herein, A series of NIR luminescent mono- or dual-lanthanide complexes were synthesized by TVPNTB ligand with lanthanide chloride salts. The monocrystalline structures of these rare earth complexes were obtained by X-ray single crystal diffraction. These lanthanide complexes are all hetero-isomorphic structures, crystallized in the monoclinic system and belong to P 21/ c space group. The phase purity was also proved by powder X-ray diffraction (PXRD). For the series of one component lanthanide complexes, the ligand TVPNTB can transfer energy to the excited state energy level of Sm3+, Nd3+, Er3+, Yb3+, Pr3+, Dy3+, and Ho3+, and produce NIR luminescence of the order of microsecond lifetime. Among them, the NIR luminescence studies of several lanthanide complexes such as Pr3+, Dy3+, Er3+, and Ho3+ are rarely reported. The results showed that the TVPNTB ligand has good near-infrared photosensitization effects on Sm3+, Nd3+, Yb3+, and Er3+. Moreover, by comparing the energy level difference of these ions, it is found that the energy level difference of Sm3+ from 4G2/5 to 6F5/2 is close to the energy level difference of Yb3+ from 2F5/2 to 2F7/2 in the ground state, and the energy level difference of Nd3+ from 4F3/2 to 4I11/2, which may lead to the cross relaxation energy transfer between rare earth ions and enhance the luminescence of Yb3+ and Nd3+. So we prepared a series of dual-lanthanide complexes, such as TVPNTB-Sm x Nd1 −x Cl3, TVPNTB-Sm x Yb1 −x Cl3 and TVPNTB-Sm x Er1 −x Cl3. Energy transfer from the antenna ligand can sensitize both NIR luminescence of the two lanthanide ions, which might serve as NIR polychromatic anti-counterfeiting luminescent barcode materials. We also investigated the energy transfer properties between the dual lanthanide ions, and confirmed that crossing relax energy transfer from Sm3+ to Nd3+, or from Sm3+ to Yb3+ were realized. The largest energy transfer efficiency ( η ) reaches 39% and 36%, leading to 4 or 2 times longer of the decay lifetimes of Nd3+ and Yb3+, respectively. Through the study of NIR luminescence performance of dual-lanthanide complexes with different proportions, it is clear that in addition to the antenna energy transfer from ligand to lanthanide ions, there is also a cross-relaxation energy transfer process from Sm3+ to Nd3+ and Sm3+ to Yb3+, thus achieving the effective energy transfer between dual-lanthanide complexes, thus further improving the NIR luminescence life of Nb3+ and Yb3+. The multi-path energy transfer strategy summarized in this study not only provides a basis for the preparation of novel high-performance NIR luminescent rare earth complexes, but also provides a reference for the design and synthesis of other multifunctional composite optical materials.

General Layer-by-Layer Assembly of Multilayered Photoanodes: Triggering Tandem Charge Transport toward Photoelectrochemical Water Oxidation.

Modulation of photoinduced charge separation/migration and construction of controllable charge transfer pathway over photoelectrodes have been attracting enduring interest in semiconductor-based photoelectrochemical (PEC) cells but suffer from sluggish charge transport kinetics. Here, we report a general approach to fabricate NP-TNTAs/(TMCs QDs/PSS)n (X = Te, Se, S) photoanodes via a facile and green electrostatic layer-by-layer (LbL) self-assembly strategy, for which transition-metal chalcogenides quantum dots (TMCs QDs) [CdX (X = Se, Te, S)] and poly(sodium 4-styrenesulfonate) (PSS) were periodically deposited on the nanoporous TiO2 nanotube arrays (NP-TNTAs) via substantial electrostatic force, resulting in the continuous charge transfer pathway. NP-TNTAs/(TMCs QDs/PSS)n photoanodes demonstrate significantly enhanced solar-driven photoelectrochemical (PEC) water oxidation activities, relative to NP-TNTAs and TMCs QDs under visible and simulated sunlight irradiation, predominantly because of the suitable energy level configuration between NP-TNTAs and TMCs QDs, unique integration mode, and high-speed interfacial charge separation rate endowed by LbL assembly. The ultrathin PSS intermediate layer functions as "molecule glue" for pinpoint and uniform self-assembly of TMCs QDs on the framework of NP-TNTAs and photosensitization effect of TMCs QDs triggers the unidirectional charge transfer cascade, synergistically boosting the charge separation/transfer efficiency. Our work offers an efficacious approach to craft multilayered photoelectrodes and spur further interest in finely tuning the spatial charge flow in PEC cell for solar-to-hydrogen conversion.

Flavonoid-sensitized photolysis of chlorothalonil in water.

Chlorothalonil is a conventional chloroaromatic fungicide and is toxic to many aquatic species. This study was designed to investigate the effects of six flavonoids on the photolysis of chlorothalonil under sunlight and artificial light. Flavonoids sensitized the photolysis of chlorothalonil under sunlight and artificial light by 6.7-18.3 and 2.4-7.5 times, respectively, in comparison with a flavonoid-free control. Photosensitization effect of each of the six flavonoids was greater under sunlight irradiation than under high-pressure mercury lamp irradiation. Cyanidin showed greater photosensitization effects than luteolin, galangin, quercetin, morin and kaempferol. Chlorothalonil underwent photo-reductive dechlorination and no hydrolysis product was formed in the presence of flavonoids. Hydroxyl and hydrogen radicals were detected in the absence and presence of cyanidin, respectively, under light irradiation. The photosensitization effect of flavonoids on chlorothalonil photolysis is apparently related to flavonoid structure and might be due to their hydrogen donation capacity. These results highlight benefit of using flavonoids to manage aquatic pollution and reduce aquatic toxicity, and have great relevance in predicting the degradation kinetics and biological impacts of chlorothalonil in surface water. © 2020 Society of Chemical Industry.

A new insight on the role of CQDs in driving BiOBr into broader-spectrum-response: Dual function of up-conversion and photosensitization effect

A carbon quantum dots modified bismuth bromide composite photocatalyst (CQDs/BiOBr) was synthesized by a mild hydrothermal method. The CQDs/BiOBr exhibited enhanced photocatalytic degradation of bisphenol A. The reason could be attributed to the broader light respond region and enhanced separation ratio of photo-induced electron-hole pairs after the introducing of CQDs. Interestingly, not only the up-conversion photoluminescence property, but also the photosensitization effect of CQDs worked together in driving BiOBr into broader-spectrum-response.

Application of Response Surface Methodology to Evaluate Photodynamic Inactivation Mediated by Eosin Y and 530 nm LED against Staphylococcus aureus.

Photodynamic antimicrobial chemotherapy (PAC) is an efficient tool for inactivating microorganisms. This technique is a good approach to inactivate the foodborne microorganisms, which are responsible for one of the major public health concerns worldwide—the foodborne diseases. In this work, response surface methodology (RSM) was used to evaluate the interaction of Eosin Y (EOS) concentration and irradiation time on Staphylococcus aureus counts and a sequence of designed experiments to model the combined effect of each factor on the response. A second-order polynomial empirical model was developed to describe the relationship between EOS concentration and irradiation time. The results showed that the derived model could predict the combined influences of these factors on S. aureus counts. The agreement between predictions and experimental observations (R2adj = 0.9159, p = 0.000034) was also observed. The significant terms in the model were the linear negative effect of photosensitizer (PS) concentration, followed by the linear negative effect of irradiation time, and the quadratic negative effect of PS concentration. The highest reductions in S. aureus counts were observed when applying a light dose of 9.98 J/cm2 (498 nM of EOS and 10 min. irradiation). The ability of the evaluated model to predict the photoinactivation of S. aureus was successfully validated. Therefore, the use of RSM combined with PAC is a promising approach to inactivate foodborne pathogens.

Photo induced anti-inflammatory activities of a Thiophene substituted subphthalocyanine derivative.

Materials that possess photo induced biological activities present opportunities for more localized, targeted and efficient treatment options that may also reduce side effects. There have been studies supporting photo induced effects of photosensitizers as anti-cancer, anti-inflammatory and anti-microbial agents. In this study, we tested photo activated anti-inflammatory effects of a Thiophene substituted subphthalocyanine (SubPc) derivative. Thiophene and its derivatives are well known for their anti-inflammatory and anti-microbial effects. There are unwanted side effects associated with Thiophene derivatives. By substituting this biologically active molecule to SubPc structure we acquired control over its activation. Upon light treatment this derivative exerted anti-inflammatory activity on the mammalian macrophages in vitro based on the substantial decrease in extracellular inflammatory cytokine levels. Our results suggest that Thiophene substituted SubPc derivative has photo induced anti-inflammatory activities. This material can be used for the treatment of patients suffering from chronic inflammation that are not associated with a bacterial burden such as autoimmune diseases and inflammatory or allergic reactions.

Hybrid Nanospheres to Overcome Hypoxia and Intrinsic Oxidative Resistance for Enhanced Photodynamic Therapy.

Photodynamic therapy (PDT) has been a well-accepted clinical treatment for malignant tumors owing to its noninvasiveness and high spatiotemporal selectivity. However, the efficiency of PDT is still severely hindered by an inherent aggregation-caused quenching (ACQ) effect of traditional photosensitizers (PSs), the presence of B-cell lymphoma 2 (Bcl-2), an antiapoptosis protein in cells, and hypoxia in the tumor microenvironment. To address these issues, hybrid nanospheres containing Fe3+, aggregation-induced emission (AIE) PS, and Bcl-2 inhibitor of sabutoclax were constructed via coordination-driven self-assembly in aqueous media. Once the hybrid nanospheres are taken up by tumor cells, intracellular O2 concentration is observed to increase via Fenton reaction driven by Fe3+, whereas intracellular PDT resistance of the AIE PS was mitigated by sabutoclax. The design of the multifunctional hybrid nanospheres demonstrates a prospective nanoplatform for image-guided enhanced PDT of tumors.

A Novel Targeting Approach for Cancer Treatment Based on Photodynamic Therapy

Over the last decades, the development of effective and selective therapies suitable for the treatment of tumors has been one of the major ambitions of scientific research. Among this multiplicity, photodynamic therapy (PDT) represents a non-invasive form of cancer treatment. Its molecular mechanism relies on the combined action of three non-toxic components: a photosensitizer (PS), light with the appropriate wavelength in the visible range and oxygen naturally dissolved in cells. The selective anticancer effect is achieved by irradiating the PS with light. The process generates cytotoxic reactive oxygen species, mainly singlet oxygen, damaging the area of PS distribution. The introduction of targeting capabilities while designing an effective photoactive compound is critical for the development of a PS-delivery system, endowed with selectivity towards cancer cells only. Furthermore, it is essential to know the location at which the damage occurred, localizing the PS molecule inside the cell environment before triggering the cytotoxic reaction. Hence, we present a protein-based nanocarrier with multifunctional capabilities for the targeting and treatment of melanoma cancer cells (A375). The system is built starting from the streptavidin-biotin complex, whose non-covalent interaction is one of the strongest known in nature (dissociation constant ≈10−14 mol/L). We functionalized streptavidin by attaching it to eosin 5-isothiocyanate, a molecule with strong photosensitizing effects, and performed FCS measurements to assess the effectiveness of the binding. The targeting ability will be introduced with the addition of a biotinylated melanocyte-stimulating hormone peptide (MSH) that binds to a receptor over-expressed on melanoma cells. Subsequently, we will administer such complex to melanoma cells and monitor the fluorescence signal of eosin on the plasma membranes, in order to follow the uptake and induce the photosensitizing effects.

Effects of photosensitizers in a high­-power, red light­-emitting diode irradiation on human gingival epithelial cells

Effects of photosensitizers in a high­-power, red light­-emitting diode irradiation on human gingival epithelial cells

A multilayered cancer-on-a-chip model to analyze the effectiveness of new-generation photosensitizers.

Three-dimensional (3D) cellular models of cancer tissue are necessary tools to analyze new anticancer drugs under in vitro conditions. Diagnostics and treatment of ovarian cancer are major challenges for current medicine. In our report we propose a new three-dimensional (3D) cellular model of ovarian cancer which can mimic a fragment of heterogeneous cancer tissue. We used Lab-on-a-chip technology to create a microfluidic system that allows cellular multilayer to be cultured. Cellular multilayer mimics the structure of two important elements of cancer tissue: flesh and stroma. For this reason, it has an advantage over other in vitro cellular models. We used human ovarian fibroblasts (HOF) and human ovarian cancer cells in our research (A2780). In the first stage of the study, we proved that the presence of non-malignant fibroblasts in co-culture with ovarian cancer cells stimulates the proliferation of cancer cells, which is important in the progression of ovarian cancer. In the next stage of the research, we tested the usefulness of the newly-developed cellular model in the analysis of anticancer drugs and therapies under in vitro conditions. We tested two photosensitizers (PS): free and nanoencapsulated meso-tetrafenylporphyrin, and we evaluated the potential of these drugs in anticancer photodynamic therapy (PDT) of ovarian cancer. We also studied the mechanism of PDT based on the analysis of the level of reactive oxygen species (ROS) in cell cultures. Our research confirmed that the use of new-generation PS can significantly increase the efficacy of PDT in the treatment of ovarian cancer. We also proved that the newly-developed 3D cellular model is suitable for rapid screening of anticancer drugs and has the potential to be used clinically in the future, e.g. in the selection of treatment methods for anticancer personalized medicine.

Кожные реакции на кардиологические препараты: клинический случай

Drug-induced photodermatitis is an important problem in a doctor's practice. This is due to the fact that a number of drugs widely used in medicine can cause the development of photodermatitis - antibiotics and sulfonamides, non-steroidal anti-inflammatory drugs, antineoplastic drugs, diuretics, antihypertensive and antiarrhythmic drugs, antidiabetic and psychiatric drugs, tretinoin and isotretinoin, as well as some others. Drug-induced photodermatitis proceeds as phototoxic reactions. In this situation, medicinal substances in the skin can act as a photosensitizer. The pathological mechanism of development of phototoxic reactions involves both an accumulation in the skin of a substance that possess effect of a photosensitizer and the simultaneous effect of solar radiation on the skin. The photosensitizer causes rashes by increasing skin sensitivity to visible or ultraviolet part of the spectrum. This article describes the case of a 64-year-old patient who developed photodermatitis while taking amiodarone for a long time.

Growing tool-kit of photosensitizers for clinical and non-clinical applications.

Photosensitizers are photosensitive molecules utilized in clinical and non-clinical applications by taking advantage of light-mediated reactive oxygen generation, which triggers local and systemic cellular toxicity. Photosensitizers are used for diverse biological applications such as spatio-temporal inactivation of a protein in a living system by chromophore-assisted light inactivation, localized cell photoablation, photodynamic and immuno-photodynamic therapy, and correlative light-electron microscopy imaging. Substantial efforts have been made to develop several genetically encoded, chemically synthesized, and nanotechnologically driven photosensitizers for successful implementation in redox biology applications. Genetically encoded photosensitizers (GEPS) or reactive oxygen species (ROS) generating proteins have the advantage of using them in the living system since they can be manipulated by genetic engineering with a variety of target-specific genes for the precise spatio-temporal control of ROS generation. The GEPS variety is limited but is expanding with a variety of newly emerging GEPS proteins. Apart from GEPS, a large variety of chemically- and nanotechnologically-empowered photosensitizers have been developed with a major focus on photodynamic therapy-based cancer treatment alone or in combination with pre-existing treatment methods. Recently, immuno-photodynamic therapy has emerged as an effective cancer treatment method using smartly designed photosensitizers to initiate and engage the patient's immune system so as to empower the photosensitizing effect. In this review, we have discussed various types of photosensitizers, their clinical and non-clinical applications, and implementation toward intelligent efficacy, ROS efficiency, and target specificity in biological systems.

Dual wavelength irradiation antimicrobial photodynamic therapy using indocyanine green and metformin doped with nano-curcumin as an efficient adjunctive endodontic treatment modality.

Indocyanine green (ICG) doped with nano-curcumin (N-CUR) can increase photosensitivity in antimicrobial photodynamic therapy (aPDT). Since metformin (Met) provides a synergistic advantage with photosensitivity, it was conjugated with N-CUR@ICG. Aim of the study was to evaluate the photosensitizing effect of N-CUR@ICG-Met used as a new photosensitizer in dual wavelengths irradiation (diode laser and light-emitting diode, LED) aPDT in root canals infected with Enterococcus faecalis biofilm. Following synthesis and confirmation of N-CUR@ICG-Met by Scanning electrone microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Zetasizer analysis, the mature microbial biofilm was formed. The quantitative and qualitative evaluations of E. faecalis biofilm were made using microbial viability and SEM analysis of the following groups of treatment modalities (n = 5): 1- N-CUR, 2- ICG, 3- Met, 4- N-CUR@ICG, 5- N-CUR@ICG-Met, 6- Diode laser, 7- LED, 8- aPDT/diode, 9- aPDT/LED, 10- aPDT/diode laser + LED, 11- aPDT/LED + diode laser, 12- 2.5 % sodium hypochlorite (NaOCl). In addition, E. faecalis not treated served as negative control. Data were statistically analyzed using One-way Analysis of Variance (ANOVA) and the post-Hoc Bonferroni tests with a level of significance set at P < 0.05. SEM, FT-IR, XRD, Zetasizer analysis confirmed successful doping of ICG-Met onto/into N-CUR. The treatment modality of N-CUR@ICG-Met mediated aPDT/diode laser, aPDT/LED, aPDT/diode laser + LED, and aPDT/LED + diode laser statistically decreased the cell viability of E. faecalis for 69.40 %, 75.52 %, 82.74 %, and 83.84 %, respectively compared with the negative control group (P < 0.05). The double wavelengths irradiation technique, which exposed the N-CUR@ICG-Met with diode laser irradiation and immediately after with LED (i.e. group No. 10), as well as, N-CUR@ICG-Met with LED irradiation and immediately after with diode laser (i.e. group No. 11) reduced the viable E. faecalis count in biofilm structures statistically more than the other treatment modalities (P < 0.05). N-CUR@ICG-Met as a new photosensitizer in dual wavelengths irradiation method may improve anti-biofilm activity of aPDT against E. faecalis.